Castle, Oklahoma, sits in USDA hardiness zones 7a-8b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Expect pecan, tomato, okra, and redbud to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Castle, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Castle lot. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Quick Facts
USDA Zones
7a-8b
Last Hard Freeze (28°F)
Feb 15
Town normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Dec 11
Town normal — light frosts arrive a few weeks earlier
Town Area
988 acres
Hardiness Zone Range
Zone maps are averages across Castle. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil varies lot by lot — soil types explained.
What Grows in Castle
Plants matched to Castle's USDA zones 7a-8b — each links to its full growing profile.





Is it too late to plant in Castle?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Jan 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 15 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 11 — long-season crops need about 90 days of runway, quick greens only 30. In a climate this gentle, “too late” hardly applies — the question becomes which crops prefer the cooler months ahead.

Growing Challenges in Oklahoma
What an experienced grower plans around here — each one has a move.

Extreme weather variability (tornadoes, ice storms, drought)
Flexible beats fortified here: row covers staged, storm-tough perennials, and quick-replant annual beds.

Red clay soils drain poorly in central OK
A raised bed ends the standing-water fight in a weekend, and fall compost keeps opening the clay below.

Low western rainfall requires irrigation
Western plots run on drip and mulch — plan the water before the planting and the dry years lose their teeth.
For cultivar selection, pest pressure, and planting-time guidance specific to Oklahoma, the Oklahoma State University Extension is the authoritative local source.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Severity Distribution
within ~10 miles of Castle
Highest-Severity Sites

A note from Gnorman
What an experienced grower watches for around here
In and around Castle, Underground Storage Tanks runs higher than the national average — 66 sites nearby. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Castle
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Castle Average
- ●USDA Zones 7a-8b
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Castle
Pull a site-specific report for your exact address in Castle, Oklahoma — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Castle, Oklahoma
- USDA Hardiness Zones: 7a-8b (USDA PHZM 2023)
- Last Hard Freeze (28°F): Feb 15 (town normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Dec 11 (town normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~299 (town normal, NOAA 1991–2020 Climate Normals)
- Land Area: 988 acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. Boundaries: US Census TIGER/Line 2025.
Frequently Asked Questions
What hardiness zone is Castle, Oklahoma?
Castle sits in USDA hardiness zones 7a-8b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
Is it too late to plant in Castle?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Jan 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 15 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 11 — long-season crops need about 90 days of runway, quick greens only 30. In a climate this gentle, “too late” hardly applies — the question becomes which crops prefer the cooler months ahead.
When does frost risk typically end in Castle?
The last hard freeze (28°F) in Castle typically lands around Feb 15, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.
When is the first frost in Castle?
The first hard freeze (28°F) in Castle typically arrives around Dec 11, per NOAA 1991–2020 climate normals — the point most tender summer crops finish. Lighter frosts usually reach a couple of weeks earlier, so watch the forecast from late summer on and harvest or cover tender plants before the first cold night.
What vegetables grow in Castle?
Castle's zones 7a-8b support a wide range — strong performers include Pecan, Tomato, Okra, Redbud, and Blackberry. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Castle, really?
Officially, Castle sits in USDA zones 7a-8b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Castle?
The federal record around Castle is a meaningful one — 70 documented sites — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Castle?
As the season closes around the first 28°F hard freeze near Dec 11 (NOAA 1991–2020 climate normals), a few moves buy time: cover tender plants with floating row cover or an old sheet on still, clear nights, water the soil the afternoon before a freeze so it holds warmth overnight, and harvest frost-tender crops like tomatoes, peppers, and basil before the first hard night. Hardy greens and root crops shrug off light frost and often sweeten after it, so leave them in.
Everything on this page is a Castle average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.
